this post was submitted on 05 Nov 2025
16 points (94.4% liked)

Ask Electronics

3881 readers
5 users here now

For questions about component-level electronic circuits, tools and equipment.

Rules

1: Be nice.

2: Be on-topic (eg: Electronic, not electrical).

3: No commercial stuff, buying, selling or valuations.

4: Be safe.

founded 2 years ago
MODERATORS
DavideAndrea@discuss.tchncs.de
linker3000@discuss.tchncs.de
16
Trivial pcb with curved trace (infosec.pub)
submitted 5 days ago by dave@feddit.uk to c/askelectronics@discuss.tchncs.de
3 comments fedilink hide all child comments
 

I’m replacing a trivial pcb in a battery pack for a small fan. It’s 6V (4xAA) with a SPST top left and a USB socket top right. But why on earth would the power line on the pcb follow that curved path? There are no other components, just the 2 ends of the battery pack and a plastic housing.

Maybe just ‘because you can’?

top 3 comments
sorted by: hot top controversial new old
[–] cmnybo@discuss.tchncs.de 30 points 5 days ago (1 children)

That trace is a fuse.

[–] hendrik@palaver.p3x.de 17 points 5 days ago* (last edited 5 days ago) (1 children)

Yes. And the meandering is probably to make it long and thin, so it trips at a low current. Maybe there's more benefits with consistency and thermal dissipation. PCB trace fuses have the obvious downside to wreck the PCB if tripped but they're for free. (And it makes sense to protect batteries in specific so they don't catch fire, so the placing close to the battery makes sense.)

[–] dave@feddit.uk 5 points 4 days ago

Ha, never thought of that. Wonder what the current is—less than what some AAs can source. Guess I’d better not find out :)